Apparatus for etching surfaces



1955 R. E. ALLEN ET AL APPARATUS FOR ETCHING SURFACES Filed May 27, 1952 Fiji. 1

1L w w 2 M! INVENQRZ ATTU/P/Vf United States Patent APPARATUS FOR ETCHING SURFACES Robert E. Allen, Dayton, and Stanley F. Hostetler, Englewood, Ohio, assignors to The Univis Lens Company, Dayton, Ohio, a corporation of Ohio Application May 27, 1952, Serial No. 290,214

3 Claims. (Cl. 41-9) Our invention relates to etching, and more particularly to apparatus for etching identifying marks into surfaces.

An object of this invention is to provide apparatus whereby a surface such as the surface on a lens can be permanently marked for identification with a mark that is imperceptible during normal use of the lens or other glass object but which can be seen by close scrutiny under the proper lighting conditions.

Another object of this invention is to provide apparatus whereby an identifying mark can be etched into a surface in a few seconds time without any special skill on the part of the person using such apparatus.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein preferred forms of embodiments of the invention are clearly shown.

In the drawings:

Fig. l is a side sectional view of a container formed in accordance with the present invention;

Fig. 2 is a perspective view of a cap for the container of Fig. 1;

Fig. 3 is a perspective view, partially in section, of the cap of Fig. 2;

Fig. 4 is a perspective view of an optical lens that has been marked by the apparatus of the present invention;

Fig. 5 is a partial side sectional view showing another embodiment of the invention; and

Fig. 6 is a perspective view of the stencil portion of the embodiment of Fig. 5.

Referring to the drawings and more particularly to Fig. l, a container indicated generally at 10 is shown partially filled with a volatile corrosive substance 11, preferably hydrofluoric acid, which has the known property of etching glass. I prefer to mix the hydrofluoric acid with wax, or the like, to add viscosity to such corrosive liquid so that it will be prevented from running out of the container in the event that it is tipped over. The container is preferably made from a type of plastic upon which the corrosive contents will have no deleterious effect. Within the upper portion 12 of the container 10, vapor or gas which is given off by the vola tile acid is normally present at room temperatures. The top of the container 10 is provided with a stopper 13 which may be removably retained in the top of the container by any suitable means.

A stencil member 14 is secured to the top of the stopper 13 as seen in Fig. 1. Such stencil member is preferably of resilient material such as rubber and is provided with apertures 15 formed through the thickness of the stencil. These apertures are formed in the shape of identifying marks, such as the letters UL, best seen in the perspective view in Fig. 2. To allow the gas or vapor to escape through the stopper 13 and to enter the mark-shaped apertures 15, a plurality of fine outlet ports 17 are formed through the stopper 13 in the area of the stopper which is in abutting relationship with the apertures formed in the gasket member 14. It is preferable to use a plu- 2,719,373 Patented Oct. 4, 1955 rality of relatively small outlet ports or holes in the stopper 13 so that such stopper presents a rigid backing to the entire area of the gasket member. Such rigid backing is required to hold the stencil member in sealed relationship with the surface being marked particularly if such surface is curved as is the case with lenses.

In Fig. 3 the operative relationship between the stopper 13 and the stencil member 14 is shown in greater detail. It will be seen that the outlet holes 17 are preferably made quite small in diameter relative to the diameters of the apertures 15 which form the identifying mark. These small holes 17 provide uniform distribution of the gas or vapor to apertures 15 and at the same time adapt the stopper 13 to provide backing for the entire area of the stencil member 14.

In Fig. 1 it should be noted that an upper surface 19 on the stencil member 14 is bowed downward by the pressure exerted upon it by the optical lens 20. Such surface 19 is resiliently bowed downward by the pressure exerted thereon by lens 20 so that the contacting surfaces conform with each other to provide a seal. In this manner the gas or vapor is prevented from spreading outwardly between the adjoining surfaces of the lens and the stencil member. Although the stencil member 14, shown in Fig. 1, has a normally fiat configuration, such member can be made convex or concave to conform with the configuration of the surfaces to be marked.

Fig. 4 is a perspective view of an optical lens on which an identifying mark has been etched into its finished surface as seen at 22. Such mark, when made according to the present teaching, is exceedingly line and precise. This is of prime importance as then the mark will be ordinarily imperceptible when a lens is in normal use, and, in fact, such marks are quite difficult to find except under close scrutiny and when the lens is held in a proper position relative to the incident light falling thereon. Hence it is seen that the identifying mark made in accordance with the present invention will in no way hamper or detract from the utility of the lens or other object upon which it has been placed. At the same time, the mark provides a means by which such lens can read ily be identified by a person who knows where to look for such mark.

The container in Fig. 5 is provided with a different type of a stencil member or cap 23. This cap is made preferably of a suitable resilient plastic material such as is used for making the container itself. In this latter embodiment the gasket member 14 of Fig. 1 has been eliminated and the cap 23 is itself provided with apertures formed in the shape of the letters or other identfying marks. It has been found that a resilient plastic cap, such as that shown at 23, will serve satisfactorily as a stencil member and that it will provide the necessary resiliency and rigidity to form the required seal between its upper surface and the surface of an optical lens which is being pressed thereto.

It should be noted that although the latter embodiment, just described, eliminates the use of the resilient rubber stencil member 14 which is used in the former embodiment, both such modifications embrace the spirit of the present invention.

In operation, the etching is done by pressing a lens firmly against the top of the gasket member so that the corrosive gas or vapor escaping through the apertures will contact the glass surface in the desired pattern so that the corrosive substance can etch an identifying mark into the glass surface. It takes one to five seconds for gaseous fluorine to etch a mark of proper depth into the finished surface of an optical lens.

While the forms of embodiments of the present invention as herein disclosed constitute preferred forms, it is to be understood that other forms might be adopted,

all coming within the scope of the claims which follow.

We claim:

1. In the etching of surfaces by the vapor phase of a corrosive substance, 21 combined container and etching apparatus comprising a container inert to the corrosive substance, a resilient stencil member carried by said container and formed with an outer surface adapted to contact and conform with variously shaped surfaces to be etched upon the application of pressure, said resilient stencil member being formed with a vapor passage communicating with the interior of said container and extending to said outer surface, a cross section of the passage conforming With the shape of the mark to be etched and said stencil member being resiliently adapted, upon said application of pressure, to form a precise pressed vapor seal at the junction of the peripheral edges of said passage with variously shaped surfaces whereby the shape of said mark can be precisely etched on variously shaped surfaces.

2. In the etching of surfaces by the vapor phase of a corrosive substance, a combined container and etching apparatus comprising a container inert to the corrosive substance, a resilient stencil member carried by said container and located above the level of the corrosive substance, said stencil member being formed with an outer surface adapted to contact and conform with variously shaped surfaces to be etched upon the application of pressure, said resilient Wall being formed with a vapor passage communicating with the interior of said container and extending to said outer surface, a cross section of the passage conforming with the shape of the mark to be I '4 etched and said stencil member being resiliently adapted, upon said application of pressure, to form a precise pressed vapor seal at the junction of the peripheral edges of said passage with variously shaped surfaces whereby the shape of said mark can be precisely etched on variously shaped surfaces.

3. In the etching of surfaces by the vapor phase of a corrosive substance, a combined container and etching apparatus comprising a container inert to the corrosive substance, 21 stencil member carried by said container including a resilient outer portion forming an outer surface adapted to yieldingly contact and conform with variously shaped surfaces to be etched and an inner portion forming a backing for said outer portion, said outer portion being formed with a passage communicating with said outer surface and of a cross sectional shape which conforms with the shape of the mark to be etched, and said inner portion being formed With a hole therethrough in communication with said passage and the interior of said container, and said stencil member being resiliently adapted, upon said application of pres- References Cited in the file of this patent UNITED STATES PATENTS Jelley July 13, 1943 Nagle Mar. 8, 1949 

1. IN THE ETCHING OF SURFACES BY THE VAPOR PHASE OF A CORROSIVE SUBSTANCE, A COMBINED CONTAINER AND ETCHING APPARATUS COMPRISING A CONTAINER INERT TO THE CORROSIVE SUBSTANCE, A RESILIENT STENCIL MEMBER CARRIED BY SAID CONTAINER AND FORMED WITH AN OUTER SURFACE ADAPTED TO CONTACT AND CONFORM WITH VARIOUSLY SHAPED SURFACES TO BE ETCHED UPON THE APPLICATION OF PRESSURE, SAID RESILIENT STENCIL MEMBER BEING FORMED WITH A VAPOR PASSAGE COMMUNICATING WITH THE INTERIOR OF SAID CONTAINER AND EXTENDING TO SAID OUTER SURFACE, A CROSS SECTION OF THE PASSAGE CONFORMING WITH THE SHAPE OF THE MARK TO BE ETCHED AND SAID STENCIL MEMBER BEING RESILIENTLY ADAPTED, UPON SAID APPLICATION OF PRESSURE, TO FORM A PRECISE PRESSED VAPOR SEAL AT THE JUNCTION OF THE PERIPHERAL EDGES OF SAID PASSAGE WITH VARIOUS SHAPED SURFACES WHEREBY THE SHAPE OF SAID MARK CAN BE PRECISELY ETCHED ON VARIOUSLY SHAPED SURFACES. 